Field of the Invention
The invention relates to a circuit configuration for a comparator having a first and second transistor connected to input and output terminals.
Such a circuit configuration for a comparator is well known. The comparator substantially includes an input-side differential amplifier with two transistors, whose load paths are connected to a reference potential on the one hand via a current source configuration and are connected by their respectively other terminals to output terminals via a current mirror configuration. The control terminal of one of the two transistors is connected to the input terminal of the comparator circuit for applying an input voltage.
Conversely, the control terminal of the other transistor is typically connected to a reference potential. Two different voltage levels can be picked up at the output terminals of the comparator circuit, depending on whether the input voltage applied to the input terminals is selected to be higher or lower than the reference voltage.
Comparator circuits are generally used to detect a voltage with respect to a reference potential. As soon as the voltage to be detected exceeds a predetermined value, the so-called threshold voltage, a signal can be picked up at the output of the comparator that indicates the exceeding of the threshold voltage, which can for instance be the aforementioned reference voltage. If conversely the threshold voltage is not reached by the input voltage at the comparator, the output of the comparator outputs a different output, so that undershooting of the threshold voltage is also signaled unambiguously at the output of the comparator.
One problem in many comparator circuits is the fact that even if no input voltage is present at the input terminals, they still consume current and thus require a constant power supply. Furthermore, the known comparator circuits are typically not connected directly to a high-voltage supply and require regulating voltages or high-precision reference voltages to function.